Merkel's four-year run atop the rankings was broken last year by Michelle Obama. But this year, by Forbes' reasoning, the first lady came in at No. 8.

As Forbes says, Merkel is "recognized as the 'undisputed' leader" of the European Union, and so she's "key to curing what ails the euro zone." Meanwhile, while Obama is "more popular than her husband," some other women from around the world rose in the rankings and that meant a slip for the first lady.

The complete top 10:

No. 1: Merkel.

No. 2: Secretary of State Hillary Rodham Clinton, who was No. 5 in 2010.

No. 3: Brazil's new president, Dilma Rousseff. She was No. 95 last year.